Abstract: Understanding the complicated issues with regard to the effects of airstream vitiation on scramjet test performance requires a lot of efforts involving experiment, modeling and CFD simulation. Based on comparative experiments for combustion in clean air and air vitiated with H₂O, massively parallel CFD simulations of reacting flowfield in the combustor for three cases corresponding to experimental conditions were conducted with a relatively detailed chemical kinetic model involving 13 species and 33 reactions. The simulated results are close to measured wall pressures of comparative experiments, and could “distinguish” the vitiation effects of H₂O in test gas. The simulated results show that for overall performance of the combustor, 7.4% H₂O and 18.3%H₂O contaminants of inflow decrease the thrust by 4.1% and 10.7% for unit air mass flow rate, and the combustion efficiency by 5.5%and 9.5%, respectively.

Key words: Scramjet; Vitiation effect; Parallel computation; Chemical kinetic model

摘要： 为了解来流污染对超燃冲压发动机性能的影响,需要大量的实验和CFD模拟。基于纯净空气和污染空气(H₂O)来流下燃烧对比实验,采用较为详细的化学反应动力学模型(13组分33方程),对三个试验条件的燃烧室反应流场进行了三维大规模并行CFD模拟。模拟结果与对比试验测得的壁面压强比较接近,能“分辨”试验气体中H₂O的污染影响。模拟结果显示,从燃烧室整体性能看,7.4%H₂O和18.3%H₂O污染导致燃烧室单位流量的空气对应推力分别下降4.1%和10.7%,而燃烧室燃烧效率分别下降5.5%和9.5%。

关键词: 超燃冲压发动机;污染效应;并行计算;化学反应动力学模型